There are a number of prior devices for automatically maintaining water in a swimming pool at a desired level. Most of the prior devices include a float valve located in a water chamber adjacent to the pool. The interior of the chamber is in open fluid communication with the pool, so that the surface of water in the chamber is at the same level as the water surface of the pool. A mechanical, magnetic, or electronic sensor adjacent to the pool detects the level of a float and in response thereto water from a water supply line is metered into the pool until the desired water level has been reached.
There are several major problems with the prior devices. The most difficult problem is that none of the prior devices can be easily retrofit to a pre-existing swimming pool, because the prior devices generally require cutting suitable holes in the pre-existing pool deck and/or pool walls and providing the plumbing necessary to provide free fluid flow between the water level sensors of the prior devices and the swimming pool water.
There is an unmet need for an inexpensive, reliable device for maintaining the level of water in a swimming pool. It would be desirable for such a device to be easily retrofit to existing swimming pools without the need to cut holes in pre-existing pool deck and/or pool wall material.